A video has emerged showing military dogs attacking a "stand in" wearing a Colin Kaepernick shirt during a demonstration at the National Navy Seal Museum in the United States.
The US Navy Seals have said that they are investigating after the video, reportedly recorded at an event in Florida last year, gained attention on social media.
American Football player Kaepernick began kneeling during the US national anthem to protest racial injustice in 2016 - he faced strong backlash at the time.
The clip has been viewed 4.6 million times so far.
The Navy Seals said the video was "completely inconsistent" with the its "values and ethos".
In a statement it said: "In the demonstration, the target is wearing a Colin Kaepernick jersey.
"The inherent message of this video is completely inconsistent with the values and ethos of Naval Special Warfare and the US Navy.
"We are investigating this matter fully, and initial indications are that there were no active duty Navy personnel or equipment involved with this independent organisation's event."
Clips were posted on Twitter on Sunday showed the dog handler, wearing the red shirt with Kaepernick's name on the back, as he was attacked by several military dogs.
In one of the videos, the dog handler appears to say: "Oh man, I will stand," after being brought down by the dogs bringing laughter from the crowd.
Kaepernick started 'taking a knee' during the National Anthem at the beginning of American Football games in 2016.
The 'take the knee' protest has since become synonymous with the Black Lives Matter movement.